Diplomatic hairdressing was one of many skills Matthew Flinders applied as he and good friend George Bass explored colonial Australia.

Flinders and Bass are the focus of a quirky look at Australia's colonial history in the Rum, Rebels and Ratbags podcast, in which 702 ABC Sydney's Dom Knight and the author of Girt, historian Dave Hunt, lay bare the intertwined lives of both explorers.

Aged 21 and 24 respectively, the young men met as ship-mates on the journey to Australia and went on to become two of the colony's earliest adventurers.

From hostility to haircuts

"Bass is this incredibly charismatic and charming man ... [who] has brought his own little boat out from Britain," Mr Hunt explained.

"It's called the Tom Thumb and the first thing they decide to do is go and explore Botany Bay.

"Flinders was a real man of the enlightenment. He really believed in developing a dialogue and friendship with the Aboriginal people."

"They meet a hostile tribe in the Illawarra who look like they're going to attack ... and Flinders diffuses the situation in only a way that Flinders could do," Mr Hunt said.

Baudin abandons his circumnavigation in Sydney because scurvy has killed a tenth of his crew and the ship's monkey.

Historian Dave Hunt

"He produces a pair of scissors and gives them all free haircuts."

On a journey south together, they discovered the passage between what is now Victoria and Tasmania, a body of water Bass had speculated upon during an earlier voyage south.

"They discover the Strait and Flinders says, 'Buddy, you were the guy who thought of this thing. I'm going to name it Bass Strait'," Mr Hunt said.

Letter hints at closeness of bond

Whether Bass and Flinders were more than friends is partly raised through the contents of a letter from Flinders to Bass, which was never received.

Bass had sailed to South America and was never heard of again, so Flinders' letter was delivered to Bass' wife.

"There was a time, when I was so completely wrapped up in you, that no conversation but yours could give me any degree of pleasure; your footsteps on the quarterdeck over my head, took me from my book, and brought me upon deck to walk with you ... and yet it is not clear to me that I love you entirely; at least my affection for Wiles reaches farther into my heart - I would take him into the same skin as me!"

With the help of Bass' distant relation, bookmaker Tom Waterhouse, the letter and its envelope, upon which there is a strident note from Bass' wife denouncing the contents, have been acquired by the State Library of NSW.

Racing the French

The French were coming and French explorer Nicholas Baudin was circumnavigating the continent, naming places and taking notes on how one might attack Sydney.

"[Joseph] Banks says to Flinders, 'I need somebody to go out and sail around the continent quicker than him', so Flinders and [his cat] Trim are actually racing Baudin and his pet monkey around Australia [between] 1801 and 1803," Mr Hunt explained.

"They meet at Encounter Bay in South Australia, named after their encounter.

"The meeting is incredibly cordial ... although Flinders speaks limited French and Baudin refuses to speak any English.

"Baudin names all of southern Australia, Terre Napoleon, which is French for Napoleon Land [but] nobody except the French takes this seriously.

"[Baudin] actually abandons his circumnavigation in Sydney because scurvy has killed a tenth of his crew and the ship's monkey."

Australia, a name born behind bars

On his way home to England, Flinders was imprisoned in Mauritius because, among other reasons, the French governor there felt the Englishman had slighted his wife by neglecting to remove his hat.

While incarcerated, Flinders completed a map which he sent to Banks in 1804, using the word Australia.

"Flinders was the first to seriously propose [the name] and popularise it ...," Mr Hunt said.

"The Admiralty takes these recommendations on board and officially renames New Holland Australia in 1824."

Flinders died in England at 40, the day after a freshly published copy of his book, A Voyage To Terra Australis, was placed into his hands.